Out of curiosity, I had a go at test-driving the design of a stopwatch.
A stopwatch should have the following capabilities:
- It can start, and begin the timer.
- It can stop, and pause the timer.
- It can reset, and set the recorded timer to zero.
- It can take a lap, which records the difference between the current time and the last lap taken.
The task is to implement a stopwatch with four methods, corresponding to the four capabilities mentioned. Additionally, there should be a
display() to show the display on the stopwatch.
The display should be in the format:
Current Time: mm:ss Lap 1: mm:ss Lap 2: mm:ss ... Lap n: mm:ss
Some questions to answer:
- How would you do this in a purely functional way?
- How would you do this using only immutable data structures?
- What constructs best represent the user interface of the stopwatch?
Have fun, and if you try this yourself, please tag me so that I can see!
Current Time: 00:00
start() // wait one second lap() // wait by two seconds lap()
Current Time: 00:03 Lap 1: 00:01 Lap 2: 00:02
November is National Blog Posting Month, or NaBloPoMo. I’ll be endeavouring to write one blog post per day in the month of November 2020 - some short and sweet, others long and boring.